Answer:
Option B, Fix the piston in place so the volume of the pas remains constant
Explanation:
As we know

The effect on variable due to another variable can be studied by keeping the third variable constant.
Hence, in order the study the variation of temperature with pressure or vice versa, the volume needs to fixed at a certain value.
Hence, option B is correct
Answer:

Explanation:
From the question we are told that:
Mass 
Charge 
Velocity 
Length of Wire 
Current 
Generally the equation for Magnetic Field of Wire B is mathematically given by



Generally the equation for Force on the plane F is mathematically given by

Therefore




Therefore in Terms of g's


Newton's third law states that for every action, there is an equal and opposite reaction. When you let go of the ballon, you are letting the force out but the force also pushes the balloon back.